Steering Stiff when Hot

[Malcolm Parker]

My initial thoughts are that if you have only 1/2" of free play at the rim of the steering wheel in the straight ahead position, to me that suggests that the worm wheel and gear are quite tightly meshed.   As you no doubt know, there is generally more wear in the straight ahead position and it is usual for things to tighten up on lock.  At least on my steering boxes!  I generally have one segment of the ribbed rim of the steering wheel as the amount of free play in the straight ahead position and I like to think all my sevens steer quite nicely.
I appreciate that this doesn't really answer your question!